In the latest version of the program it is not possible to minimize it to the system tray. The program always ends up getting in the foreground and it is always necessary to minimize manually (What over time can end up being something boring). So to solve this problem I found a solution. A program that is able to minimize any system window to the tray called 4t Tray Minimizer. An easy to install, lightweight, useful and malware free program.
Check out his analysis on Virus Total
I hope I was helpfull! 